1. Field of the Invention:
The present invention relates to a bicycle simulation system used for traffic safety education and training, games, physical training, or the like.
2. Description of Background Art:
Simulation systems corresponding to respective vehicles have been proposed for simulated experience of operations of an airplane, an automobile, a motorcycle, a bicycle and the like. Some of the simulation systems have been put to practical use. In a bicycle simulation system, a rider seated astride a saddle of a dummy bicycle works the pedals to thereby perform a simulated cycling. The rotation of the pedals is detected by a speed sensor to determine the simulated velocity or the like, whereby a simulation process is executed. In a vehicle simulation system, it is preferable, for enhancing realism, to display on a monitor screen a scene varied according to the simulated running velocity and to generate a mimic sound.
In the bicycle simulation system, when scenery varied according to the simulated running velocity is displayed on a monitor, the realism is improved. A picture processing computer for displaying the scenery on the monitor is comparatively large because it includes a recording medium for storing a large amount of data, a picture processing arithmetic board and the like. Therefore, the picture processing computer is installed as a body separate from the dummy bicycle.
On the other hand, the dummy bicycle is provided with electric apparatuses such as a speed sensor. Therefore, a controller is provided for carrying out control processes for the electric apparatuses. The controller is connected to the picture processing computer. In a bicycle simulator for training, such a controller is provided at a fixed type steering handle portion (see, for example, Japanese Patent Laid-open No. 2001-87417).
A bicycle is capable of calm operation, since it does not have any drive source such as an engine, a motor, etc. On the other hand, a one-way clutch provided at a rotary shaft of the rear wheel generates an intermittent ratchet mechanism notch sound “click-clack” according to the difference between the rotation speed of a drive sprocket and the rotation speed of the rear wheel. This sound is a characteristic sound at the time of riding a bicycle. When such a notch sound is generated in a bicycle simulation system, the realism is favorably enhanced.
A dummy bicycle used in a bicycle simulation system may be provided with a flywheel operated in conjunction with the pedals so as to exert an appropriate load on the pedals. Therefore, a real notch sound can be generated by providing the flywheel with a one-way clutch. However, depending on the design conditions of the flywheel and the gear ratio, the rotation speed of the flywheel at the time of a predetermined simulated running velocity is not necessarily equal to the rotation speed of the rear wheel of a real bicycle at the same running velocity. In addition, the rotation speed of the flywheel may be different from the rotation speed of the rear wheel in a situation (for example, a descending slope) assumed in the simulated cycling. The notch sound generated from the one-way clutch at the flywheel may give the rider a sense of incompatibility.
For generating a mimic sound of a vehicle, there has been proposed a system for generating a sound similar to an actual engine sound by detecting an accelerator operation amount and using a fluctuation processing, a sound transmission path simulating process, a sound synthesizing process for synthesizing a plurality of engine sounds, and the like (see Japanese Patent Laid-open No. Hei 10-277263).